DE1551312B2 - DEVICE FOR GENERATING KELTE - Google Patents

Description

The invention relates to a device for generating cold at very low temperatures with at least one cylinder, the one hand

ίο with a cooler and on the other hand with a freezer is connected, in which cylinder between the cooler and freezer at least one preparation of a paramagnetic substance is arranged, which is surrounded by a magnet and in heat-exchanging There is contact with a medium column, which in operation has a higher specific heat than the preparation and can be moved back and forth in the cylinder by means of at least one driven piston, the movement of the piston and the magnetization or Demagnetization of the preparation are coordinated in such a way that the medium column at the Magnetization generated heat to the cooler and the cold generated during demagnetization to the freezer transported.

From US-PS 25 89 775 such a device is known in which a preparation of a ferromagnetic The substance is alternately magnetized. The entropy of a ferromagnetic substance in one Magnetic field with a certain field strength is lower than that in a magnetic field with the field strength Zero. This means that in order to keep the temperature constant, the preparation is subjected to heat during magnetization must be removed and heat must be added during demagnetization.

Besides ferromagnetic substances there are also other substances that have such a caloric effect have and are therefore suitable for use in a device of the type mentioned. Cold can can also be generated, for example, by adiabatic demagnetization of paramagnetic substances, which is known in principle from US-PS 29 13 881, and by adiabatic depolarization of paraelectric substances or by magnetizing a superconductor (US Pat. No. 3,119,236).

In the device according to US-PS 25 89 775 the reciprocating medium column is used only as a means of heat transfer developed by the magnetization of the ferromagnetic preparation Heat from this preparation to the cooled area and that generated during demagnetization Cold transported by the preparation to the place to be cooled.

The known device has the disadvantage that the thermal efficiency is low.

The invention aims to provide an improved device with high thermal efficiency.
This object is achieved in that the stroke of the piston is dimensioned so that one end part of the medium column at the temperature of the cooler and the other end part of the medium column at the temperature of the freezer, with their respective inner limits, just reach the cooler or the freezer The intermediate part of the medium column located between the two end parts acts as a regenerator in which the temperature drops from the temperature of the cooler to that of the freezer.

3 4

In this way it is achieved that only the two medium columns contain and in which the preparation is made

End parts of the medium column for the transport of a paramagnetic substance into a magnetic field

Serve heat or cold, while the intermediate part can be moved in and out,

forms a regenerator. In this regenerator, F i g. 5 a schematic representation of a

Heat from the preparation is stored when the preparation 5 direction for generating cold, which several in

Prepared from the temperature of the cooled area, preparations arranged in a row from a paramagnetic

the temperature of the place to be cooled contains cooled table material,

is, so when moving the medium column in the direction of F i g. 6 and 7 a schematic representation or towards the cooled area. At the opposite a cross-sectional view of a device for the direction of movement the medium column gives the reio evidence of the cold that is generated in a cylinder the preparation removes this heat again. Removable double-acting piston contains, wherein through this, a high thermal efficiency is achieved - at each end of the cylinder there is a channel, closes, in which there is a cooler, a preparation

A favorable embodiment of the device a paramagnetic substance and a freezer loading

is characterized in that on both sides of the 15, the channels on the freezer side with

Preparation between this and the cooler or are connected to each other and the two preparations

Stabilizers through which the freezer can flow are attached using a magnet with rotating poles in

are arranged. Antiphase magnetized or demagnetized.

As a result, convection in the regenerator intermediate In Fig. 1, 1 denotes a cylinder. In

part of the medium column at the moment there are two pistons 2 and 3, which are located around this cylinder 1

in which the intermediate part is located between the piston rod 4 and 5 with a not shown

The preparation and the cooled or cooled gearbox are connected, which is the two

Location. Convection in the intermediate part would move the piston in phase,

the temperature prevailing over the intermediate part. In the cylinder 1 there is also a preparation 6

gradient and thus the thermal efficiency 25 from a paramagnetic substance. This preparation

affect the device. is gas permeable. On both sides of the specimen 6

As a filling compound for the stabilizers, for. B. stabilizers 7 and 8 are arranged. These are

Bead or gauze layers into consideration. gas-permeable masses with possibly the same

Another favorable embodiment of the pre-structure like that of the preparation 6

direction is characterized in that the pre-30 cooler 9 and a freezer 10 are present. To that

ready is movable in a second cylinder, around preparation 6 is an electromagnet 11 with a variable

which a magnet is arranged, the thermally conductive variable field is arranged. In cylinder 1 is located

is connected to the freezer and its coil between pistons 2 and 3 is a medium column,

from one at the temperature of the cooler supra- This medium has been chosen so that it is at the

There is conductive material, with the second 35 conditions prevailing in operation compared to the

Cylinder a ring is arranged, which is also material of the preparation 6 a high specific

thermally connected to the freezer and made of heat.

a superconducting at the temperature of the cooler. The mode of operation of this device is based on Material is made and where the magnet and the principle that with a paramagnetic substance the ring at such a distance from one another causes a change in the magnetization of this substance are ordered that the preparation causes its end entropy change, in such a way that the If there was material inside the magnet or the ring, it was warmer when it was magnetized and warmer when it was undone, magnetize gets colder. When the heat generated

Another favorable embodiment of the advance to a cooler and the generated cold to a direction is characterized by the fact that the pre-45 can be promoted, then you have one

Preparations are arranged in two channels that are received on the refrigerator. The heat and cold trans-

Side of the cooler in the cylinder on both sides of the port takes place in the device according to F i g. 1 through

Piston open out and on the side of the freezer with the reciprocating medium ..

are connected to one another, and that the preparations in In the in F i g. 1 are the situation shown the two channels with the rotating poles of a 50, the piston is in its extreme right position.

Magnets work together in such a way that the cooler 9 has a certain temperature, which is with

alternating one and the other preparation between the help of an additional cooling

the poles. systems, e.g. B. a gas refrigerator is obtained.

Embodiments of the invention are shown in the The freezer is supplied depending on the Drawings are shown and are shown below

described in more detail. It show heat assuming a temperature that is lower

F i g. 1 and 2 are a schematic representation of one other than that of the cooler.

Device for generating cold, with a measurement The diagram sketched under the device

dium under the influence of two in phase shows the temperature profile in the device, moving piston through a preparation of a 60 From I to II (end part) the temperature of the prevails

paramagnetic substance is moved back and forth, cooler 9. From III to IV (end part) the prevails

F i g. 3 shows a schematic representation of a pre-temperature of the freezer 10.

direction for generating cold, which is to the back and the intermediate part II-III of the medium column as Moving the medium around with a double acting regenerator effective. The temperature runs in it the flask is provided 65 from the cooler temperature to the freezing temperature. F i g. Fig. 4 is a schematic representation of an arrangement when the pistons move to the left The preparation 6 is used to generate cold, which catches you twice, with the help of the magnet acting piston for reciprocating an 11 magnetized. The preparation heats up in the process.

5 6

The amount of heat V is transferred to the medium. The transition from the situation in FIG. 1 on

gen. When the column of medium moves to the left, which the F i g. 2 the magnetic field is varied in such a way that

the amount of heat V reaches the cooler 9, where it, ",. ,, H ₁ ... ~ .. ^,,

^e ,, <?.,. . , ⁵ 'that the expression ——T ₇ for the preparation

is discharged. Τ— Θ ^v

F i g. 2 shows the situation in which the piston 5 remains constant on average. As a result, the main remains in its extreme left position. The gnetisation of the preparation is constant, and the amount of heat V is dissipated through the cooler. The desired magnetocaloric effects are avoided in the rhyme preparation 6 and in the stabilizer (partially) present generator. Herein means
There is more heat in the _{H = matic} field strength, which acts as a regenerator,
Intermediate part IMII of the Medmmsaule stored. io _{T =} ^^ _abso , _{ute temperature of the} preparation,

The temperature of this regenerator part is little _{Q = paramagnetic} Curie temperature of the pre-

vary as the medium narats' a large heat capacity Has.

The preparation is at the freezer temperature. The remanent magnetic field is when it is reached

If the pistons move to the right, this becomes the situation in FIG. 2 turned off.

The preparation is demagnetized with the aid of the magnet 11. In this device, the medium consists of

and the preparation becomes colder. a gas that is under a pressure that is higher

The amount of cold VI reaches the right movement as its supercritical pressure. Gases have the

movement of the flask into the freezer 10, where this property that they are at very low temperature and cold

can serve to give an object at low 20 high pressure a large specific heat per volume

Keep temperature. During this movement the lumen will have unity. The operating conditions must

Intermediate part H-III of the medium column the preparation conditions to be such that no phase transition in the

Give off heat, so that this takes place again on the cooler-solid state,

temperature reached. Instead of a gas, the medium is also a liquid

Since pistons 2 and 3 move in phase, the conditions must then be usable

the volume of the medium column does not change. be chosen that no phase transition during operation

Due to the large heat capacity of the medium, this liquid is carried out.

the temperature will be almost constant. As a result, with the device according to FIG. 1 and 2 can be on

the medium pressure is also reduced in an almost constant simple manner using the magnetocalo

Have value. 3 ° ric effect generated cold in one continuous process

The stabilizers 7 and 8 have to be taken care of.

that the medium quietly into the preparation 6 and instead of a preparation from a paramagnetic

flows out of it, moreover, they must

ensure that the intermediate part II and III of the electrical or superconducting material can be used,

The medium column does not flow back and forth into the energy, which is alternately electrified and magnetized,

freezes or the cooler gets. F i g. 3 shows an apparatus for generating

The temporary storage of an amount of heat, the cold, which in broad outline of the Fig. 1, compared to the cooling capacity of the device is high. The device contains a cylinder 31 in which, by means of the part of the gas which acts as a regenerator, a gas-permeable preparation 36 from a paradium column forms an essential part of the cycle. 4 ° magnetic fabric is located. The capacity of the cycle without this regenerator on both sides with a stabilizer 37 or 38 would be low. It can be seen that there is an upper limit. The cylinder 31 connects via a cooler with the known regenerators 39 and a freezer 40 to a cylinder 43, which serve to generate a periodic gas flow in which a displacer 44 can be moved.
heat or cool down. The surprising thing about this 45 A magnet 41 provides the necessary change that in the present case at very low temperatures of the magnetic field.

Both a gas and a liquid can be used. The mode of operation of this device can be used to convert a solid material to the device according to FIG. 1 and 2.
standing specimen at a higher temperature F i g. FIG. 4 shows a schematic representation of a device to be brought to a lower temperature and this device for generating cold, which, likewise afterwards, to the original temperature again, like the device according to FIG. 3, is heated in one. The displacer 44, which is displaced by the solid substance, can be moved for forward heating and is temporarily provided in the gas or in the liquid and moving the column of medium. The saved. To cool the preparation, the device also contains a cylinder in which then only one cold source, a freezer 40 and a cooler 39, which are fixedly arranged around the regeneration units, are required, as is the case with a regenerator. Between the freezer and the cooler, if proper heat transfer does not occur, a gas-permeable paramagnetic balance can be found. Preparation 36. This preparation 36 is between two

The possibility of using gas or liquid masses 46 provided with channels 45. The preparation

is based on their high heat capacities and the two masses 46 are rigid with one another

compared to those of many solids at low temperatures, this structure is connected to one with one

doors. ■ not shown gear connected piston

In the cycle, for the sake of simplicity, rod 47 is attached in advance. In the channels 45 are pipes

set that the variation of the magnetic field can be shifted by a minimum of 48, which occurs on the cooler 39 or the device

times to a maximum of (Fig. 1) and a maximum of 65 freezer 40 connect. The tubes 48 together form

minimal (Fig. 2) in both cases almost in the menu with the channels 45 the stabilizers,

the movement of the pistons changes direction, around the cylinder there is a magnet 41,

he follows. this field is not changed.

7 8

This magnet is at the end of a sleeve 42 made of Die enteinem highly thermally conductive material such. B. copper, wrapped heat is through the moving Memontiert, the other end of which is thermally conductive with the medium from the preparation 53 to the preparation 52 and 40 is connected to the freezer. As a result, the Ma preparation 51 is diverted to the cooler 62. The heat spreads up to approximately the same temperature as the 5 of the preparation 53 enters the preparation 52 and the freezer is cooled. The cooler 39 is z. B. with is reversed by a part of the cold developed during demagnetization with the help of a gas refrigeration machine down to about 10 ° K,
cools. In this cooling temperature of the freezer has the warmth of the preparation 52 is accommodated in the Enteine temperature of about 3 ⁰ K. magnetization in the preparation 51st

The magnetic coil is made of niobium-tin, io In this way a cooling device is obtained.

which is superconducting at the cooling temperature, so that when each of the successive prepa-

a strong magnetic field can be obtained. rate is effective at a lower temperature,

The change in the magnetization of the specimen so that finally the specimen 53 at very low

36 is obtained in that the preparation generates cold by means of temperature.

the rod 47 is displaced, making it more 15 in the F i g. 6 and 7 is a device for

or less gets into the magnetic field. testify to cold shown schematically at the one

On the sleeve 42 is a ring 50 made of niobium in a cylinder 74 movable displacer 75 a

Tin arranged. At the end of the movement of the pre-medium column in two connected to the cylinder 74

parates 36 down is this just moved in channels 76 and 77, each channel depending

Ring 50. ao a cooler 78, a first stabilizer 79, a prep

Before the magnetic field was entered 80, a second stabilizer 81 and a freezer were switched on, the ring 50 is in the superconducting state. On the freezer side are the ones that have been brought in, so that no channels 76 and 77 communicate with one another within the sleeve.
Magnetic field prevails. The magnetization of the pre- In this device the mediumparates moves is then equal to zero. 25 column in channel 76 during one half of a

The operation of the device corresponds to the cycle from cooler 78 to freezer 82, while Principle of the device according to the previous one - it is located in the other channel from the freezer to the quenching Characters. ler moved there. That means the changes

F i g. 5 shows a schematic representation of one of the magnetization of the preparations 80 in both channels

Device for generating cold, which must be several 30 len with each other in phase opposition, since the

Paramagnetic preparations 51 arranged in series, medium flows in the two channels one below the other

52 and 53, all of which are in antiphase with one of them. This would be three separate

Neten magnets 54, 55 and 56 can be carried out with a variable magnet.

Work together field. However, this is using a magnet

Each of the preparations is passed through 35 with rotating poles 84 and 85 on both sides. In a stabilizer 57, 58, 59 and 60 flanked. One half of the cycle is surrounded by the poles Cylinder 61, in which the specimens and the stabilization- the specimen in channel 77 and in the other half gates are included, closes on one side in channel 76. In this way, one receives one over a cooler 62 and on the other side multiple device for changing the magnetic field, via a freezer 63 at the two ends of a 40. One advantage of this device is that the two Cylinder 64, in which a displacer 65 moving sides of the displacer are at cooling temperature, so is cash. that leakage losses of the displacer do not

The magnets 54, 55 and 56 will result in losses at the same time. There are also few line connections

aroused, or the excitement is removed when lust occurs. Another advantage is that the

the displacer 65 changes its direction. 45 magnetic field is used well.

For this purpose 3 sheets of drawings

Claims (4)

Patent claims: 1. Device for generating cold at very low temperatures with at least one Cylinder connected on the one hand to a cooler and on the other hand to a freezer, in which cylinder between cooler and freezer at least one preparation of a paramagnetic Substance is arranged, which is surrounded by a magnet and in heat-exchanging contact stands with a medium column that has a higher specific heat than the preparation during operation and reciprocable in the cylinder by means of at least one driven piston is, the movement of the piston and the magnetization taking place when it is reversed or demagnetization of the preparation are coordinated in such a way that the medium column the heat generated during magnetization to the cooler and that during demagnetization generated cold transported to the freezer, characterized in that the stroke of the piston (2, 3; 44; 65; 75) is so dimensioned is that at the temperature of the cooler (9; 39; 62; 78) located one end part (I-II) and the other end part (III-IV) of the freezer (10; 40; 63; 82) located at the same temperature Medium column with their respective inner boundaries the cooler (9; 39; 62; 78) or the Just reach the freezer (10; 40; 63; 82), the one between the two end parts (I-II; III-IV) located intermediate part (II-III) of the medium column acts as a regenerator, in which the temperature depends on the temperature of the cooler (9; 39; 62; 78) drops onto that of the freezer (10; 40; 63; 82). 2. Apparatus according to claim 1, characterized in that on both sides of the preparation (6; 36; S1, 52, 53; 80) between this and the cooler (9; 39; 62; 78) or the freezer (10; 40; 63; 82) through which flow stabilizers (7, 8; 37, 38; 45, 48; 57, 58, 59, 60; 79, 81) are arranged are. 3. Apparatus according to claim 1, characterized in that the preparation (36) in one second cylinder is movable, around which a magnet (41) is arranged, which conducts heat with the freezer (40) is connected, and its coil from one at the temperature of the cooler (39) consists of superconducting material, a ring (50) being arranged around the second cylinder, which is also thermally connected to the freezer (40) and consists of one at the temperature of the Cooler (39) made of superconducting material, and wherein the magnet (41) and the ring (50) are arranged at such a distance that the preparation (36) in his End positions located within the magnet (41) or the ring (50). 4. Apparatus according to claim 1, characterized in that the preparations (80) in two channels (76, 77) are arranged on the side of the cooler (78) in the cylinder (74) to both Sides of the piston (75) open and are connected to one another on the side of the freezer (82), and that the preparations (80) in the two channels (76, 77) with the rotating poles (84, 85) of a magnet work together in such a way that one and the other preparation alternate located between the poles.